Once upon a time, most mountain bikes still rolled along the world’s trails with inner tubes. Then, in 2001, Stan’s had the brilliant idea of putting a special sealant into the tires, rendering conventional inner tubes useless. With this experience under their belt, Stans decided to develop their first tubeless specific wheelset. Fast forward a couple of decades, and the entire MTB world rolls on tubeless wheels, and in the meantime, the American has added a whole range of tubeless wheels to their portfolio, including the Flow MK4 alloy model we tested. They’re available both as a 29” and 27.5” variant, making it easy to put together a mullet wheelset. Moreover, you can choose to run either a Shimano or SRAM freehub, paired with either 6-bolt or Centerlock brake disc mounts. Our 29″ Flow MK4 test wheelset tips the scales at 1,882 g (with rim tape) and retails at € 949.99.
The Stan’s Flow MK4 wheelset employs a Flow MK4 rim, which is manufactured from durable 6069 aluminium with a welded joint and reinforced spoke bed. Like most Stan’s wheels, the Flow MK4 relies on their proprietary BST-Asymmetric rim design. As the name suggests, the asymmetric rim shape and offset spoke holes ensure better stability compared to a conventional rim. In addition, the asymmetrical profile allows you to use same length spokes on both sides, simplifying maintenance significantly. The rims are paired with Stan’s in-house M-Pulse hubs, which feature six pawls equipped with Neodymium magnets for optimal alignment. According to Stans, this should reduce resistance and improve the engagement of the pawls. With the pawls engaging every 1.66°, the hub transfers the power almost instantly to the wheel, minimising the dead spot in the pedal stroke. The hub and rims are held together by conventional J-bend spokes, which get their name from the 90° bend in the spoke head and are designed to withstand greater tensile and compressive loads.
Stans provided us with three Flow MK4 alloy wheelsets for this test, which we put through the wringer over several months and with different bikes, from nimble trail rockets to potent enduro bruisers. First off, not even the sturdiest wheelset in this world is guaranteed to survive a cased landing or a nasty rock garden with a flat tire. All the wheelsets we tested took a real beating, both on our home trails and during countless bike park sessions – and even had to face the odd enduro race. Except for one rear wheel, which exploded with a nasty landing, all of them survived this test unscathed, coming out on the other side with just a few superficial scratches on the rim that bear witness to months of abuse. That said, none of the rims has dents or loose spokes. We always paired the wheels with robust tire casings like MAXXIS’ DoubleDown or Schwalbe’s Super Gravity. On the trail, the Stans Flow MK4 impressed us with a discreet ride feeling, while the small engagement angle ensures direct power transfer, especially when pedalling. The freewheel sounds like a swarm of bees, but the buzzing sound isn’t too intrusive on the trail.
Our conclusions about the Stan’s Flow MK4 wheelset.
With the Stan’s Flow MK4, the godfather of tubeless offers a wheelset that was developed specifically for tough enduro riding. Even after many months of abuse on the roughest trails, our test wheels are still running smoothly, without any major damage. Thanks to the small engagement angle, the hub transfers the power directly to the wheel when pedalling. The Stan’s Flow MK4 alloy wheelset might not be cheapest, but it delivers a strong performance on the trail.
Tops
- Excellent trail performance
- Small engagement angle
- Available in all conventional wheel sizes
Flops
- Relatively expensive
For more info, please visit notubes.com.
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Words: Mike Hunger Photos: Mike Hunger
About the Author
Mike Hunger
From slopestyle and landscape photography to enduro and action shots. Mike enjoys trying new things and loves action. He also loves craftsmanship, regularly going on road trips with his VW Syncro van, which he restored and converted himself. Of course, his bike and his camera are always with him so that he can ride the finest trails from Italy to the Alps and capture the most beautiful moments. Thanks to his training as an industrial mechanic, his experience in cycling and his photographic skills, he can apply his know-how perfectly as a bike journalist, testing the latest bikes and components and documenting his findings. As a photography nerd, he also captures the reviews with his camera and ensures that the magazine features only the best images.
